Coordination Funds

3022研究单元的持续目标是深入了解使用引导超声波（GUW）并考虑到机器学习方法的金属纤维层压板（FML）中的集成半自主结构健康监测（SHM）。这需要在复杂的环境条件下，对波传播的物理现象，它们与隐藏损伤的相互作用，在事件位置使用微技术传感器记录这些相互作用，以及用于全面损伤诊断的信号处理有一个整体的看法。这些发现将有助于考虑和全面理解由大阻抗差异组成的所有层状材料系统中的波传播。金属纤维层合板中引导超声波的研究是当前研究的热点。近年来，研究人员开发了一些新的方法来模拟引导超声在FML中的传播。然而，结构健康监测方法几乎没有解决FML。2021年开发了一个模型，用于预测具有集成粘弹性层的FML对冲击或振动响应的行为。除此之外，许多关于纤维增强聚合物中SHM的研究正在进行中，这些研究使用了与研究单元直接相关的嵌入式装置，但没有解决各向异性、非均匀介质（如FML）的问题。然而，这种各向异性是FOR 3022的一个主要科学问题。第二个资助期的另一个主要任务是相控阵换能器的集成，它允许通过GUW对FML进行定向激励。此外，考虑到生产引起的阻抗跳变，即导致额外的面内不均匀性的拼接。

The continued aim of the Research Unit FOR 3022 is to gain a profound understanding of an integrated semi-autonomous Structural Health Monitoring (SHM) in Fibre Metal Laminates (FML) using guided ultrasonic waves (GUW) taking into account methods of machine learning. This requires an integral view on the physical phenomena of wave propagation even under complex environmental conditions, their interaction with hidden damage, recording of these interactions using microtechnical sensors at the location of event, and a signal processing for full damage diagnostics. The findings will be useful for the consideration and comprehensive understanding of wave propagation in all layered material systems made from components of large impedance differences. The investigation of guided ultrasonic waves in fibre metal laminates is subject to current research. Novel methods for simulating guided ultrasonic wave propagation in FML are developed within the last few years. However, structural health monitoring approaches are hardly addressed for FML. A model to predict the behaviour of FML with an integrated viscoelastic layer on impact or vibration response was developed in 2021. Apart from that, a lot of research is going on concerning SHM in fibre reinforced polymer using embedded setups which is directly linked to the research unit but does not address anisotropic, inhomogeneous media such as FML. However, this anisotropy is a major scientific issue of the FOR 3022. Another main task of the second funding period ist the integration of phased array transducers, which allow for a directed excitation of the FML by means of GUW. Additionally, production-induced impedance jumps, i.e. splices which lead to an additional in-plane inhomogeneity, are taken into account.